Birds fly in the foreground as a plume of ash and steam rise from Popocatepetl volcano, as seen from San Andres Cholula, Mexico, Wednesday. Mexico's Popocatepetl volcano is continuing to spout gases and hot rock fragments and it is dusting towns on its flanks with volcanic ash.

Mexico City — When Mexicans shudder with fear, they are usually thinking about decapitated bodies, stories of family members being kidnapped for ransom, or other consequences of the nation's deadly drug war.

But today, it is the image of erupting volcanoes and trembling homes that has captivated their attention.

With four earthquakes or aftershocks over 6.0 in four months, and now Popocatepetl volcano spewing ash, water vapor, and rock fragments into the air, catastrophes have officially overtaken public security as what's most on the public mind, according to a new survey by the polling group Con Estadistica and media company Grupo Formula in Mexico City.

In the national poll carried out this month, 65 percent of respondents cited catastrophes and accidents as one of the top three things on their minds, while public security was indicated by 48 percent of respondents. The presidential elections slated for July 1 trailed at a distant third, at 28 percent. Unfortunately, some of the more joyous images, like recent Easter vacations, only ranked at one percent.

These shifting concerns are easily understood: Mexico raised the alert level for Popocatepetl, known as “Popo” to locals, after hot rock fragments were hurled into the air early this week.

The dome of the volcano, which sits at nearly 18,000 feet just southeast of Mexico City, began to expand Friday, according to the National Center for Disaster Prevention.

The volcano's last major eruption occurred in 2000, forcing the evacuation of tens of thousands of residents who live at the base of the peak. Volcanic activity has increased this year, and experts say that while it is a scary prospect, it can help prevent a larger-scale disaster as the plumes of water and ash release mounting pressure.

The series of quakes in western Mexico, including a March 20 noon tremblor of 7.4, felt as far away as Mexico City has some optimistic-minded Mexicans relieved that tension is being released, but as Don Blakeman, a geophysicist with the Colorado-based US Geological Survey says, that pressure release doesn't foretell what will happen along the rest of the faultline.

And for the pessimists out there, the earth's movements make it easy to keep focusing on when it could tremble again. That's why, as the new poll shows, earthquakes are what's most on people's minds, with 50 percent of respondents citing seismic activity, far surpassing any other singular issue on the Mexican political and social scene.